Surgical fastener apparatus

ABSTRACT

An instrument for cutting body tissue and applying a plurality of two part surgical fasteners to the body tissue on each side of the cut. The instrument includes a U-shaped distal portion, and a body having a longitudinal portion for enclosing an axial drive means for pushing fasteners into position in the body tissue. The axial drive means is off-centered from the fastener pushing means in the fastener cartridge at the U-shaped distal portion. A trigger operated diverter is provided with a unique system of force conversion and transmission for converting a single off-centered axial drive force to a uniformly distributed drive force for pushing the fastener pushers, and the knife assembly.

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention relates to an apparatus for applying a plurality ofsurgical fasteners to body tissue and more particularly to an apparatusfor simultaneously applying a plurality of two part bioabsorbablesurgical fasteners.

2. Description of the Prior Art

Surgical fastener applicator apparatus in which surgical fasteners aresimultaneously applied to body tissue are known. Typically, thesedevices include a fastener holder positioned on one side of the tissueto be fastened and an anvil parallel to the fastener holder positionedon the other side of the tissue. Typically, means is provided forlinearly translating the fastener holder and the anvil toward oneanother to clamp the tissue between them. Means in also provided fordriving the fasteners from the fastener holder so that the ends of thefasteners pass through the tissue and form finished fasteners as theymake contact with the anvil assembly, thereby producing an array offinished fasteners in the tissue.

Also in use are instruments for applying two part fasteners having afastener portion and a retainer portion. The fastener portion generallyhas barbed prongs for penetrating body tissue and engaging correspondingopenings in the retainer portion. Once engaged, the fastener andretainer are locked together. Such two-part fasteners are usuallyconstructed from bioabsorbable material.

In common use are apparatus in which the fastener holder and anvil areremovably mounted in or on an actuator for supporting and actuating thecartridge. The apparatus can be disposed of after a single use or it canbe reused for another surgical fastening procedure after cleaning,sterilizing and reloading with a fresh cartridge. Also in use are fullydisposable surgical instruments in which the cartridge and actuator arepreassembled ready for use and disposed of after only a single use.

U.S. Pat. No. 4,665,916 (Green) describes a surgical fastener apparatusfor applying rows of fasteners laterally through hollow body organs suchas the thorax, trachea, stomach, uterus or intestines. The cartridgeincludes an alignment pin which achieves and maintains proper relativepositioning of the fastener holder and anvil components thereof. Whenthe fully assembled instrument is actuated, it is positioned in such away that the body tissue to be fastened is clamped in place between thestaple-ejecting surface of the fastener holder and the anvil assembly.The clamping pressure exerted against both sides of the tissue issufficient to provide effective hemostasis along two linear sites which,upon "firing" of the instrument, receive substantially parallel rows offasteners on either side of an incision formed by a tissue cutting knifewhich is also incorporated in the holder. The deployment of the knife ismechanically synchronized to immediately follow the insertion of thefasteners.

U.S. Pat. No. 4,819,853 (Green) discloses a surgical fastener applicatorwhich includes tissue gripping elements provided along the sides of aknife slot to prevent body tissue from pulling away from the fastenersafter the latter are positioned in place and the incision is made.Thereafter, clamping pressure is released.

U.S. Pat. No. 4,881,545 (Isaacs et al.) discloses a surgical fastenercartridge possessing an improved body cutting knife assembly. The knifeelement of the assembly is held in permanent locking engagement with aknife holder.

U.S. Pat. No. 4,767,044 (Green) discloses a fastener applying apparatusincluding means for preventing all of the fasteners from reaching peakformation force at the same time in order to reduce the maximum forcerequired to operate the apparatus.

U.S. Pat. No. 4,728,020 (Green et al.) discloses an articulated surgicalfastener applying apparatus having a linear drive mechanism which isoffset from the centerline of movement of the surgical fasteners. Thedrive force is proximally directed, i.e. it is a pulling forcetransmitted by a tensioned cable mechanical rather than by a drive rod.

While the prior art instruments, such as those mentioned above, havebeen serving the needs of the medical community by providing surgeonswith quick and simple means to make and/or seal incisions in bodytissue, improvements are nevertheless desirable. For example, surgeonsprefer to have a greater visibility of the area of tissue upon whichthey are operating. It should be noted that in the prior artinstruments, the drive rod for driving the fastener pushers operatesaxially and is centered at the rear of the fastener holding cartridge.The longitudinal frame of the instrument, therefore, often interfereswith the surgeon's line of sight and obstructs visibility of theoperation site.

An off-centered axially moving drive rod would therefore be desirablesince it would enable the surgeon to have greater visibility of theoperating site. Up to now however, the use of an off-centered drive rodhas not been recognized as a solution to the problem. Unlike the cabledrive means, the drive rod operates by applying a distally directed, or"pushing" drive force. The central location of the drive rod of theprior art instruments prevents the fastener pushers and the knife, ifthere is one, from pivoting and jamming within the fastener holdingcartridge due to the critical location of the force. Such jamming wouldoccur if the fastener pushers were driven by an off-center force inpreviously known instruments. Moreover, cable drive means restrict theability of prior art instruments to be "reset" after initial firing.

The present invention provides such an apparatus in which improvedvisibility of the operation site is facilitated while avoiding directoff-centered driving force application to the fastener pushing members.

SUMMARY OF THE INVENTION

Apparatus for substantially simultaneously applying a plurality ofsurgical fasteners to body tissue or the like, which comprises a bodyhaving a longitudinal portion enclosing axial drive means, a distalportion thereof defining a tissue reception aperture. Anvil means ispositioned at the distal portion of the tissue reception aperture andfastener holding means is pivotally mounted relative to the anvil meansadjacent one end portion thereof and defines a space therebetween. Thefastener holding means contains a plurality of surgical fastenersarranged in generally parallel rows extending generally transversely tothe longitudinal portion and the longitudinal portion is generallyoffset from the center of the rows of staples. Means is provided forinitially advancing the fastener holding means distally at leastsufficient to contact body tissue positioned within the aperture, andmeans is provided for reception of proximally directed user appliedforce and for translating same to distally directed drive force on theaxial drive means generally in alignment with the longitudinal portion.The invention comprises means for translating the distally directeddrive force to distally directed staple drive force distributedgenerally uniformly over the length of the plurality of staples to applythe staples to the body tissue.

In a preferred embodiment, the apparatus disclosed herein forsubstantially simultaneously applying a plurality of surgical fastenersincludes a handle; a trigger means for applying the fasteners; a bodywith a longitudinal portion enclosing an axial drive means; a U-shapeddistal portion; an anvil assembly positioned at the distal leg of theU-shaped distal portion; a fastener holding cartridge pivotally mountedrelative to the anvil assembly and adjacent one end of the anvilassembly thereby defining a gap between them, and containing a pluralityof surgical fasteners, and optionally including a knife means forcutting body tissue. The apparatus further includes approximating meansfor actuating the fastener holding cartridge; and a fastener pushingmeans for substantially simultaneously pushing all of the fasteners fromthe fastener holding cartridge. The apparatus is characterized in thatthe axis of the longitudinal portion of the body is in off-centeralignment relative to the axial centerline of movement of the fastenerpushing means, and said apparatus further includes means for translatingan off-centered axial drive force of an evenly distributed driven forceacross the proximal end of the fastener pushing means.

The U-shaped distal portion of the apparatus is defined by two U-shapedplate portions of frame means mounted in parallel spaced apart relationto each other, the mutually facing surfaces of the plate portions beingflat. The two U-shaped plate portions are connected by a spacer pintransversely mounted therebetween at the ends of their respectiveproximal legs. The said plate portions of the frame means and the spacerpin cooperate so as to align the anvil assembly with the fastenerholding cartridge.

The knife means possesses a distally facing elongated surface forcontacting the proximal end of the fastener pushing means, the distallyfacing elongated surface of the knife means abutting and moving saidfastener pushing means in response to the distal movement of the axialdrive means.

The fastener pushing means includes a pusher plate which issubstantially flat on two opposite sides and which has a plurality offastener-pushing members distally projecting from a back proton, andinterference means associated with at least one of the flat sides forfrictionally engaging a cooperating surface of the fastener holdingcartridge to prevent the fastener pusher plate from moving proximallyafter it has been moved to its most distal position in response tomovement of the axial drive means. The interference means can comprisesone or more detents projecting from the side of the pusher plate.

The anvil assembly includes a retainer mounting bar comprising anelongated bar having a plurality of mounting posts projectingtransversely from said bar, said posts being frictionally engageablewith the retainers for holding said retainers in a fixed positionrelative to the instrument until said retainers are fully engaged withtheir respective fasteners.

Although the preferred embodiment described herein pertains to aninstrument for substantially simultaneously applying the fasteners, itis also envisioned as being within the scope of the present inventionfor the instrument to apply the fasteners sequentially. Furthermore,although two-part bioabsorbable surgical fasteners are referred tohereinbelow, instruments for applying other types of surgical fastenersincluding non-bioabsorbable staples and the like are contemplated asbeing within the scope of the present invention. Additionally, althoughthe embodiments described hereinbelow are described in conjunction withthe fasteners and retainers, it is within the scope of the presentinvention to provide an instrument in an unloaded condition, such as areloadable instrument with replaceable fastener and retainer means.

BRIEF DESCRIPTION OF THE DRAWINGS

Preferred embodiments of the invention are described hereinbelow withreference to the drawings wherein:

FIG. 1 is a perspective view of the fastener applying apparatus of thepresent invention;

FIG. 2 is a perspective cut-away view of the apparatus of the presentinvention;

FIGS. 3, 4, 5, and 6 are exploded perspective views of the fastenerapplying mechanism of the apparatus;

FIG. 7 is a perspective view of the retainer support arm of theapparatus;

FIG. 8 is a perspective view of the retainer mounting strip of theapparatus;

FIG. 9 is an enlarged perspective view of the two part surgical fastenerwhich can be applied to body tissue by means of the apparatus of thepresent invention;

FIGS. 10, 11, 12 and 13 are elevational views partially cut-away,sequentially illustrating the fastener application with the apparatus ofthe invention;

FIGS. 14 and 15 are cross-sectional views of the fastener cartridge andanvil assembly, illustrating the operation of the apparatus in prefiredand fired conditions, respectively; and

FIG. 16 is an elevational cut-away view of the fastener cartridge andanvil assembly after the apparatus has been fired.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Referring initially to FIGS. 1 to 4, left and right body portions, 10and 20 respectively, provide means for housing the actuating mechanismof the invention and also provides means for allowing the user to holdthe instrument. Each body portion has a handle portion, 11 and 21 forthe left and right body portions respectively, and a longitudinally oraxially extending portion 12 and 22, respectively. The body portionsalso each have internal struts 23 which include recessed portions 23aassociated with the internal wall surface of the handle. The strutsprovide added strength and support. The recessed portions 23a receiveand hold the frame extension 50 in a fixed position. Aperture 25 in theright body portion and a corresponding aperture in the left body portionreceive trigger pivot pin 140 shown in FIG. 3. Recessed portions 24 and14 of the right and left body potions form a slot for receiving thepivot arm 151 of safety catch 150.

Referring to FIG. 3, left frame 60 is an elongated member having anaxially extending longitudinal portion 63; a proximal portion 61 whichis inclined from the longitudinal portion and which defines aperture 62for receiving trigger pivot pin 140; a U-shaped distal portion 64 havinga distal leg 64a, a proximal leg 64b, aperture 64c for receivingshoulder rivet 70, and apertures 64d for receiving rivets 250 formounting to the retainer housing 240 (see FIG. 6); and notch 65 forengaging one of the detents 211 of the spring retainer 210.

Referring now to FIG. 4, right frame 30 is an elongated member having anaxially extending longitudinal portion 33; a proximal portion 31 whichis inclined from the longitudinal portion and which possesses anaperture 32 for receiving trigger pivot pin 140; a U-shaped distalportion 34 having a distal leg 34a, a proximal leg 34b, aperture 34c forreceiving shoulder rivet 70, and apertures 34d for receiving rivets 250for mounting to the retainer housing 240 as shown in FIG. 6; and notch35 for engaging one of the detents 211 of the spring retainer 210 asshown in FIG. 4. Additionally, right frame 30 is fixedly mounted toframe extension 50 such that both have aperture 32 in common. Frameextension 50 has an indentation 51 on its distal edge for accommodatingthe pivot arm 151 of safety latch 150.

Referring now to FIG. 6, left and right frames 60 and 30, respectively,are mounted in a parallel spaced apart relationship to each other. Thedistal U-shaped portions define the U-shaped distal end of theinstrument. The mutually facing surfaces of the distal portions of theframes are flat thus eliminating intermediate components andfacilitating improved component alignment and minimizing dimensionaltolerance variations. This is in contrast to prior art instruments inwhich similarly shaped distal plates possessed inward indentations orjogs to demarcate the distal leg which supported an anvil assembly oflesser width than the fastener holder. In the prior art instruments (seee.g. U.S. Pat. No. 4,665,916) alignment of fastener components and bodytissue was provided by a longitudinally mounted alignment pin whichpierced the body tissue being fastened. In the present inventionalignment is facilitated by the provision of closer tolerances betweenthe flat inner sides of the frames and the fastening holder, by spacerpin 70 which maintains a predetermined distance between the ends ofproximal legs 64b and 34b, and through the use of a material ofconstruction for the frames which ensures that the frames will neitherdeform nor fatigue during use. Preferably, the frames are constructedfrom stainless steel having a thickness of at least 0.07 inches andpreferably of from 0.07 to 0.08 inches. Parallelism and close tolerancesare thereby maintained for proper alignment of the fastener holder withthe anvil.

In FIGS. 10 and 11, spacer pin 70 extends laterally between the proximallegs 64b and 34b of the left and right frames, and projections 71 arereceived into apertures 64c and 34c. Spacer pin 70 spaces the left andright frames apart at a fixed predetermined distance and serves as aguide for the fastener holding cartridge.

Referring to FIGS. 2 and 3, actuator 80 serves as part of the fastenercartridge actuation means, i.e. approximating means to move the fastenercartridge from a proximal open position such that body tissue can befreely inserted into the gap between the fastener cartridge and theanvil assembly, into a distal closed position wherein it can hold bodytissue clamped between it and the anvil assembly, as discussed below.Actuator 80 is a lever pivotally mounted to the left and right bodyportions 10 and 20 by means of a pin 230 disposed through aperture 81.Aperture 82 receives pin 90 for mounting lever rod 110. Actuator 80 hasa forked distal end 83 and a longitudinal central slot 84. Thumb rest 85is at the proximal end.

Lever rod 110 is an elongated member defining longitudinal central slot111. Lever rod 110 is slidably mounted within slot 84 of the actuator bymeans of pin 90 disposed through aperture 82, washer 100 and slot 111.

Trigger 130 is an elongated lever arm having a forked end with curvedhook-like members 131 shown in FIG. 3. Central slot 132 extendslongitudinally along the underside of the trigger 130. Side slots 133are provided for engaging the snap prongs 154 of the safety catch 150.Central slot 132 is provided in trigger 130 for receiving trigger insert120, which is mounted therein. Trigger insert 120 has an aperture 121which is aligned with the curved hook-like members 131 such that triggerpivot pin 140 is received therethrough. Trigger insert 120 has an endwith projection 122 for contacting the proximal end of lever rod 110.

Referring once again to FIGS. 2 and 3, trigger pivot pin 140 istransversely mounted with left and right ends fixed respectively inapertures 25 in the interior surfaces of the left and right bodyportions 10 and 20, and is disposed respectively through apertures 62,121, and 32, of the left frame, trigger insert and right frame.

Referring to FIG. 4, safety catch 150 includes panel 153, andprojections 152 for pivotally mounting into corresponding apertures inthe left and right body portions.

Referring to FIGS. 4, 10 and 11, clamp 160 is an elongated member withlongitudinal central slot 161. Cap 170 is mounted on the proximal end ofclamp 160 with vertical slot 171 of the cap being aligned withlongitudinal slot 161 of the clamp to permit passage therethrough oflever 110. Cap 170 preferably has a sloped proximal surface 172 forbeing contacted by the forked end 83 of the actuator. Clamp 160 has atransversely extending aperture 162 for receiving clamp pin 90.

Thrust bar 180 is an elongated member which is slidably mounted withinslot 161 of the clamp. Thrust bar 180 has a longitudinal slot 181through which clamp pin 90 is disposed. Proximal end 183 is forcontacting the distal end of lever 110. Distal edge 184 is forcontacting the cam assembly discussed below and is preferably inclinedto facilitate camming action between it and link 340. Thrust bar 180 hasa distally projecting post 182 for mounting a washer 190, and coiledspring 200.

Spring retainer 210 is a block shaped piece having longitudinallyextending detents 211 for engaging slots 65 and 35 in the left and rightframes. The proximal ends 212 serves as a backstop for spring 2200 suchthat spring 200 biases the slidable thrust bar 180 in the proximaldirection. The distal end has a curved portion 213 for receiving a leafspring 220.

Retainer pin 231 extends transversely across the underside of the leafspring 220 and is fixed at its ends in corresponding apertures in thebody portions. Retainer pin 231 maintains the spring 220 in a fixedposition.

Referring additionally to FIGS. 5 and 6, the fastener holder 460 of thepresent invention is an assembly which includes several unique features.

The cam assembly, which is housed within the fastener holder 460, is anon-torquing force diverter comprising an assembly of links and a camplate which converts the off-centered axial drive force to a balancedlinear drive force uniformly distributed across the proximal end of theknife blade assembly. With such means for providing this conversion, theneed to provide an off-centered drive force directly to the knifeassembly is avoided. Such last mentioned force application method wouldresult in unbalanced force and unwanted torque which would pivot and jamthe knife and fastener pushers. Moreover, in the present invention,force transmissions and conversions are provided through compressionmembers thereby facilitating definitive and accurate force transmissionand conversion. Furthermore, tension cables or the like as utilized inprior developments are avoided.

Referring to FIG. 5, the cam assembly includes curved link 340 having adistal end pivotally mounted in socket 331 in the fastener cartridge 330by means of pin 370 disposed through aperture 341. The proximal end oflink 340 is pivotally attached by a pin 360 disposed through aperture342 to one end of an intermediate link 350. The other end of theintermediate link 350 is pivotally attached by a pin 360 to cam bar 380.Cam bar 380 has a flat distal camming surface 381, a rear projection 382with aperture 383 for receiving a pivot pin 360, and upper and lowerbolts 384 and 385 which project into and ride along the inclined slots291, 292, 301, and 302 of the right and left side plates. The flatdistal camming surface 381 of the cam bar is for contacting the proximalsurface 421a of the back of the blade channel 420.

The movement of the cam bar has a vector component linearly aligned withthe path of movement of the fastener pushers 410, knife 440, and bladechannel 420. Unaligned components of motion are not transmitted to theblade channel 420 because the cam bar's distal surface 381 remains in aperpendicular orientation relative to the center line of movement of thefastener pushers 410 and blade channel 420, and because the cammingsurface 381 is slidable relative to proximal surface 421a.

Referring once again to FIG. 5, the knife blade assembly, also housedwithin the fastener holder 460, includes blade channel 420, leaf spring390, blade holder 430, and knife blade 440.

Blade channel 420 has two parallel dovetail shaped portions 424projecting distally from a back portion 421. The dovetail portionsdefine apertures 422 for engaging projections 432 of the blade holder430. Together, dovetail portions 424 define a channel 423 in which leafspring 390 is located. The back portion 421 has a proximal surface 421afor contacting the distal camming surface 381 of the cam bar, and adistal surface 421b which is contacted by leaf spring 390.

Curved leaf spring 390 is located between the blade holder 430 and theblade channel 420. Its ends are retained by inwardly projecting stubs321 of the cartridge cap 320. Spring 390 contacts the distal surface421b of the back of the blade channel 420, thereby biasing the bladechannel 420 proximally.

The distal end of blade holder 4320 has a slot 431 for mounting a knifeblade 440. Projections 432 on the side of the blade holder are mountingfixtures received into apertures 422 of the blade channel.

Knife blade 440 has a sharp distal edge 441 for cutting body tissue. Theproximal edge of blade holder 430 shown in FIG. 5 is mounted in slot 431of the blade holder.

Referring once again to FIG. 5, cartridge pushers 410 are substantiallyflat strips having distal pointing finger-like projections 411 forpushing the fasteners through slots 332, and out of the cartridge 330into engagement with their respective retainers 280 in the anvilassembly. At least one side of each pusher possesses an interferencemeans, such as one or more detents 412, which frictionally engage thesurface 335 of the corresponding slot in the fastener cartridge 330 inwhich the pusher slides. (See FIG. 15.) These detents advantageouslyprevent the pushers from retracting once they have been moved to theirmost distal position, thereby preventing the fasteners from migrating ordeflecting back into slots 332. Such migration or deflection, ifunimpeded, may result in non-engagement of the fastener with itscorresponding retainer. The proximal edges 413 are contacted by surfaces433 of the blade holder such that when the blade holder is moveddistally, surfaces 433 urge the fastener pushers 410 towards the distaldirection.

Fastener holder 460 also comprises cartridge 330 having a plurality offastener slots 332, a knife slot 333, a rear slot 334 through which thedistal end 184 of the thrust bar enters, and socket 331 for retainingdistal end 341 of the curved link.

Cartridge cap 320, which is mounted to cartridge 330, has inwardlyprojecting stubs 321 for retaining the ends of the leaf spring 390.

Left and right side plates 330 and 290 respectively each have twoinclined slots (301 and 302 in side plate 300; 291 and 292 in side plate290) for retaining the bolts 384 and 385, which are slidably receivedtherein. Said slots are defined by guide surfaces (301a, 302a, 291a,292a, respectively) which contact the circumferential surfaces of therespective ends of the bolts disposed therethrough and restrain themovement of the bolts to a predetermined linear path. The width of theslots 301, 302, 291, and 292 closely match the width of the respectivebolts 384 and 385 while leaving enough clearance for free sliding of thebolts. Slots 304 and 294 receive cartridge pivot pin 260, whichpivotally mounts the fastener holder 460 to the frame. Slots 303 and 293receive bosses 36 of the inner sides of the respective frames. Pins 310are disposed respectively through apertures in the left side plate 300,the cartridge cap 320, the cartridge 330, and the right side plate 290.

The anvil assembly comprises retainer support arm 240, anvil block 400,retainer holding strips 270, and retainers 280. Arm 240 is mountedbetween the distal arms 64a and 34a of the frames by means of pins 250disposed through corresponding apertures 241 in the arm 240, andapertures 64d and 34d in the frames. Aperture 242 in the arm receivescartridge pivot pin 260. In other embodiments, the anvil assembly caninclude a means for replacing retainers (for example inreusable/reloadable instruments), or crimping means (for example, withmetal staples).

Referring additionally now to FIG. 9, two-part bioabsorbable surgicalfasteners useful in the present invention generally comprise a fastenerportion 450 having a backspan 451, and prongs 452 with barbs 453 at thetips thereof. The fasteners are initially located in slots 332 of thecartridge. When the pusher members 410 are distally moved, thefinger-like projections 411 each contact the backspan 451 of a fastener450, thereby moving it through and out of its respective slot 332. Theretainer portion 280 of the two-part fastener comprises a base 283 withcolumnar members 282 having apertures 281 for receiving the barbedprongs 452 of the fastener. Once engaged, the fastener and the retainerlock together, hence the desirability of constructing them ofbioabsorbable material such as polyglycolide, polylactide or copolymersthereof for suturing body tissue.

Referring again to FIG. 6 and additionally to FIGS. 7 and 8, retainers280 are preferably mounted on retainer mounting strips 270 in arm member240 such that each retainer is aligned with a corresponding fastenerportion in the respective fastener slots 332. Mounting strip 270includes a plurality of mounting posts 271 each of which frictionallyengages a respective aperture 281 of the retainer. Mounting strip 270also includes projections 273 which ride in a corresponding slot inretainer support arm 240, and which serve as a limiter to preventlateral sliding of the mounting strip. Hook-shaped catches 272 snap intowindows 243 of the retainer support arm 240 thereby preventing theretainer mounting strips 270 from dropping out of the support arm 240.Mounting strip 270 is thus adapted to be loaded with retainers prior toits introduction into retainer support arm 240. This externalretainer-loading feature of mounting strip 270 is particularlyadvantageous because the retainers are typically quite small, e.g.,about 0.2 inches in length, and are therefore difficult to handle.Mounting strip 270 permits retainers to be conveniently mounted ontomounting posts 271 and then the entire mounted assembly is easilysnapped into retainer support arm 240. Reloading of mounting strip 270is also facilitated by simply removing the mounting strip from theretainer support arm, mounting fresh retainers, and repositioning withinretainer support arm 240.

Preferably, at least two rows of retainers 280 are mounted in an arm240. The rows are separated by an anvil block 400 which provides a meansfor contacting body tissue and providing a backstop surface 401 for thecutting edge 441 of the knife. When the barbed prongs 452 enter the topof the column members 282, the posts 271 are pushed out of the oppositeend of the apertures 281 by the entering barb 453, and thereby disengagethe retainer 280, releasing it from the anvil assembly.

Referring to FIGS. 10 to 13, the instrument is initially in the open andunfired condition illustrated in FIG. 10. For use in surgical operationsit is positioned by the surgeon such that the body tissue to be fastenedis located in the U-shaped distal portion between the jaws of theinstrument, i.e. in the gap between the fastener holder 460 and theanvil assembly. The surgeon then actuates the instrument: by pivotingactuator lever 80 down (i.e. clockwise as shown) from the position shownin FIG. 10 to the position shown in FIG. 11. By this movement, thefastener holder 460 will move distally to a closed position wherein itcontacts the body tissue (not shown) to secure the body tissue in afixed position. Moving the actuator lever 80 down also moves the clamp160 forward and aligns lever 110 along the longitudinal axis of theinstrument. The distal end of clamp 160 contacts the fastener cartridge460 and moves it from the open position to a closed position. It shouldbe noted that until lever 110 is aligned, the fasteners cannot be fired.

The instrument at this point is in the condition illustrated by FIGS. 11and 14. The next step for the surgeon is to release the safety catch 150by pivoting it down (counter-clockwise as shown), thereby putting theinstrument in a "ready to fire" condition.

To fire the instrument, the surgeon pivots the trigger lever 130(counter-clockwise as shown) by manual application of a proximallydirected force. This movement, in turn, pivots trigger insert 120 andconverts the proximally directed force to a distally directed force suchthat portion 122 moves lever 110 distally. Lever 110 pushes the thrustbar 180 distally, and thrust bar 180 presses on link 340. This motion istransferred by link 350 to cam bar 380. Cam bar 380 has a path ofmovement defined by slots 291, 292, 301, and 302, all of which arealigned in the same predetermined direction. The vector components ofmotion of the cam bar include a vector component linearly aligned withthe center line of motion of the knife assembly and fastener pushers410. Although the path of movement of the cam bar 380 is in adirectional line which is at an angle from the center line of movementof the knife assembly and fastener pushers, it does not exert pivotal ortorquing motion of these parts. Torque is avoided because the cam bar isconstrained to an orientation perpendicular to that of the abovementioned center line of movement by the relatively close fit of thebolts 384 and 385 within their respective guide slots 291, 292, 301, and302, and because the distal surface 381 of the cam bar will slide acrosssurface 421a, thereby preventing unaligned vector components of cam barmotion from being transmitted to blade channel 420. Thus the forceconversion and transmission is positive and accurate due to the precisemovement of compressor members in engagement with each other.

The blade channel 420 is moved forward by the cam bar 380 and surface433 pushes the fastener pushers distally, thereby driving the fastenersout of the slots, and into the retainers. Detents 412 on the fastenerpushers 410 frictionally engage the surface 335 of their respectiveslots in cartridge 330. This frictional engagement prevents the fastenerpushers from returning to their proximal position after they have beenmoved to their distal position. Knife blade 440 is moved distallythrough slot 333 thereby cutting any body tissue 470 (shown in FIG. 15)between the knife and the anvil block 400 which the knife edge 441impinges. The instrument thereby creates an incision into body tissuewhich is sealed by a row of fasteners on each side.

The prongs 154 of the safety catch snap into locking engagement withslots 133 of the trigger and thereby prevent inadvertent firing of anunloaded instrument.

The instrument is now in the fire position illustrated by FIGS. 12 and15.

Referring now to FIGS. 13, 15 and 16, to open the instrument and releasethe body tissue, the surgeon pivots the actuator lever 80counterclockwise into the upward position as shown in FIG. 13. The knifeassembly, being biased proximally by spring 390, retracts into thefastener holder 460. The fastener holder 460 moves back to an openposition thereby releasing the body tissue. The thrust bar 180 and clamp160 return to their proximal position because of the biasing force ofspring 20.

The instrument can be made of any size suitable for its purpose offastening body tissue, and the various parts can be made of materialsappropriate to their function. For example, the body, actuator lever,and trigger can be injection molded from a high strength polymer. Theframes, cam assembly, fastener pushers, and blade channel can beconstructed from an appropriate metal.

The instrument has application in a full range of surgical applicationsincluding abdominal, gynecological, pediatric, and thoracic surgery forresection and transection. In a preferred embodiment, the instrumentincludes bioabsorbable fasteners and retainers and has application inthe creation of a temporary opening such as hysterotomy, to align thetissue layers and minimize bleeding during a cesarean delivery.

While the above description contains many specific details, thesedetails should not be construed as limitations on the scope of theinvention, but merely as examples of preferred embodiments thereof.Those skilled in the art will envision many other possible variationsthat are within the scope and spirit of the invention as defined by theclaims appended hereto.

What is claimed is:
 1. Apparatus for substantially simultaneouslyapplying a plurality of surgical fasteners to body tissue, whichcomprises a body having a distal end and a proximal end and having alongitudinal portion enclosing axial drive means for transmitting adistally directed drive force, a distal portion of said apparatusincluding a tissue reception space; anvil means for closing fasteners,said anvil means being positioned at the distal portion of said tissuereception space; fastener holding means for initially holding saidsurgical fasteners, said fastener holding means being pivotally mountedrelative to said anvil means adjacent one end portion thereof anddefining said tissue reception space therebetween, said fastener holdingmeans containing a plurality of surgical fasteners arranged in generallyparallel rows extending transversely to said longitudinal portion, andsaid rows being movable distally along respective paths each path havinga centerline generally parallel to said longitudinal portion, saidcenterlines defining a center plane and said longitudinal portion beinggenerally offset from said center plane; means for initially advancingsaid fastener holding means distally at least sufficient to contact bodytissue positioned within said aperture;actuation means for reception ofa proximally directed user applied force and for translating same todistally directed drive force on said axial drive means generally inalignment with said longitudinal portion; means for translating saiddistally directed drive force to distally directed fastener drive forcedistributed generally uniformly over the length of the rows of saidplurality of fasteners to apply said fasteners to the body tissue.
 2. Anapparatus for substantially simultaneously applying a plurality ofsurgical fasteners to body tissue, including a handle; trigger meansmovable in response to a user applied drive force for transmitting saiddrive force to an axial drive means, said axial drive means transmittingsaid drive force distally along a lengthwise path; body means with alongitudinal portion enclosing said axial drive means, said body meansincluding a distal end and a proximal end; a U-shaped distal portionhaving a distal leg; an anvil assembly positioned at the distal leg ofthe U-shaped distal portion; a fastener holding cartridge pivotallymounted relative to the anvil assembly and adjacent one end of the anvilassembly thereby defining a gap between them and containing a pluralityof surgical fasteners and optionally including knife means for cuttingbody tissue; the apparatus further including approximation means foractuating the fastener holding cartridge; and fastener pushing means forsubstantially simultaneously pushing all of the fasteners from thefastener holding cartridge, said fastener pushing means having aproximal end and being linearly movable along a path having an axialcenterline of movement in response to drive force applied to saidproximal end; and said apparatus being characterized in that:thelengthwise path of the distally directed drive force transmitted by thedrive means is in off-center alignment relative to the axial centerlineof movement of the fastener pushing means, and said apparatus furtherincludes means for translating said distally directed drive force to anevenly distributed drive force across the proximal end of said fastenerpushing means.
 3. The apparatus of claim 2 wherein said means fortranslating said distally directed drive force comprises:a movable cambar having a distal camming surface; a surface for receiving movementfrom the off-centered path of said axial drive means; means including atleast one pivotable link for transmitting movement from said axial drivemeans to the cam bar; means for maintaining said distal surface of thecam bar in an orientation substantially perpendicular to the centerlineof movement of the fastener pushing means; and means for transferringmotion from said distal camming surface to said fastener pushing means.4. The apparatus of claim 3 wherein said means for maintaining saiddistal surface of the ca bar in said substantially perpendicularorientation comprises at least one first member which projects from thecam bar and which is fixedly attached thereto, and at least one secondmember associated with the fastener holding cartridge, said secondmember having at least one guide surface contacted by said first memberfor restraining the movement of the first member to a predeterminedpath.
 5. The apparatus of claim 4 wherein said second member isstationary relative to the fastener holder.
 6. The apparatus of claim 5wherein said second member comprises a side plate having a slot definedby said at lest one guide surface.
 7. An apparatus for substantiallysimultaneously applying a plurality of two-part surgical fasteners tobody tissue, said two-part surgical fasteners each having a fastenerportion and a retainer portion, said apparatus including a handle; atrigger means for receiving a user applied force; a body with alongitudinal portion enclosing an axial drive means for transmitting adrive force along a lengthwise path; a U-shaped distal portion having adistal leg; an anvil assembly for holding the retainers, said anvilassembly being mounted at the distal leg of the U-shaped distal portion;a fastener holding cartridge pivotally mounted relative to the anvilassembly adjacent one end of the anvil assembly thereby defining a gapbetween them and containing a plurality of fasteners and optionallyincluding a knife means for cutting body tissue; the apparatus furtherincluding approximating means for actuating the fastener holdingcartridge; and a fastener pushing means for substantially simultaneouslypushing all of the fasteners from the fastener holding cartridge; andsaid apparatus being characterized in that:the U-shaped distal portionof the apparatus is defined by two U-shaped plate portions of supportingframe means mounted in parallel spaced apart relation to each other andhaving flat mutually facing surfaces and proximal legs with end portionsextending above said fastener holding cartridge, said two U-shaped plateportions being connected by a spacer pin transversely mountedtherebetween at the end portions of their respective proximal legs, andsaid plate portions of the frame means and said spacer pin cooperatingso as to align the anvil assembly with the fastener holding cartridge.8. The apparatus of claim 7, wherein said U-shaped plate portions arefabricated from stainless steel having a thickness of at least 0.07inches.
 9. An apparatus for applying a plurality of surgical fastenersto body tissue, said apparatus having a distal end and a proximal endand comprising:a body with a longitudinal portion enclosing an axialdrive means for translating a distally directed drive force along alongitudinal path through said body; a handle associated with said body;a trigger means associated with said body for receiving a user appliedforce and; an anvil assembly; a fastener holding cartridge pivotallymounted relative to the anvil assembly adjacent one end of the anvilassembly thereby defining a gap between them, said fastener holdingcartridge containing a plurality of surgical fasteners and including aknife means for cutting body tissue, said knife means being distallymovable in response to movement of the axial drive means; approximatingmeans for actuating the fastener holding cartridge; and a fastenerpushing means responsive to movement of the drive means for pushing thefasteners from the fastener holding cartridge said fastener pushingmeans being movable along a path, the centerline of said fastenerpushing means path being non-collinear with the centerline of said drivemeans path; means for translating said drive force from said drive meansto a force evenly distributed along a proximal surface of said fastenerpushing means; wherein said knife means possesses a distally facingelongated surface for contacting the proximal end of the fastenerpushing means, said distally facing elongated surface of the knife meansabutting and moving said fastener pushing means in response to thedistal movement of the axial drive means.
 10. The apparatus of claim 9wherein said knife means comprises a knife blade with a distal cuttingedge and a proximal edge fixed to a blade holder which is slidablymounted within the fastener holding cartridge, said blade holder havingat least one distally facing elongated surface parallel to and on eachside of said knife blade.
 11. The apparatus of claim 9 wherein saidfastener pushing means comprises at least one pusher plate having aplurality of distally projecting flat finger-like projections, eachprojection being for pushing a respective one of the fasteners from thefastener holder cartridge.
 12. An apparatus for applying a plurality ofsurgical fasteners to body tissue, said apparatus having a distal endand a proximal end and comprising:a body with a longitudinal portionenclosing an axial drive means for transmitting a drive forcelongitudinally through said apparatus; a handle associated with saidbody; a trigger means associated with said body for receiving a userapplied force; an anvil assembly; a fastener holding cartridge pivotallymounted relative to the anvil assembly and being adjacent one end of theanvil assembly thereby defining a gap between said fastener holdingcartridge and said anvil assembly, said fastener holding cartridgecontaining a plurality of surgical fasteners and optionally including aknife means for cutting body tissue, said knife means being distallymovable in response to movement of the axial drive means; approximatingmeans for actuating the fastener holding cartridge; and fastener pushingmeans for pushing the fasteners from the fastener holding cartridge,said fastener pushing means including a pusher plate movable from aproximal position to a distal position in response to movement of theaxial drive means and which is substantially flat on two opposite sidesand which has a plurality of fastener-pushing members distallyprojecting from a back portion and interference means associated with atleast one of the flat sides for frictionally engaging a cooperatingsurface of the fastener holding cartridge to prevent the fastener pusherplate from moving proximally after said plate has been moved to saiddistal position in response to movement of the axial drive means, saidfastener pushing means having a centerline of movement non-collinearwith said axial drive means; and directing means for converting thedrive force transmitted by said axial drive means to a drive forceevenly distributed to the fastener pushing means.
 13. The apparatus ofclaim 12 wherein said interference means comprises at least one detentprojecting from the side of said pusher plate.
 14. A fastener holdingcartridge for use in an instrument for applying a plurality of surgicalfasteners, which comprises:a housing having a distal end and proximalend and containing a plurality of surgical fasteners, each fastenerbeing slidably mounted within a slot; fastener pushing means which ismovable in a path having a centerline of movement for linearly pushingsaid fasteners from their respective slots in response to application ofan off-centered linear drive force provided by drive means which ismovable in a linear path which is non-collinear with the centerline ofmovement of the fastener pushing means; redirecting means for convertingthe off-centered drive force to a drive force evenly distributed to thefastener pushing means, said redirecting means including a surface forreceiving the off-centered drive force, a means for transmitting saidforce to a cam bar, said cam bar having a substantially flat distalsurface for contacting the fastener pushing means and having a path ofmovement with a vector component aligned with the path of movement ofthe fastener pushing means, and said redirecting means further includingmeans for restraining the orientation and movement of the cam bar suchthat the distal surface of the cam bar remains perpendicular relative tothe centerline of movement of the fastener pushing means.
 15. Thefastener holding cartridge of claim 14 wherein said fastener pushingmeans comprises at least one pusher plate having a plurality of distallyprojecting, flat, finger-like projections, each projection being forpushing a respective one of the fasteners from said fastener holdingcartridge.
 16. The fastener holding cartridge of claim 15 wherein saidpusher plate is movable from a proximal position to a distal positionand has interference means for frictionally engaging a cooperatingsurface of the fastener holding cartridge when said pusher plate is insaid distal position to prevent said pusher plate from returning to itsproximal position.
 17. The fastener holding cartridge of claim 16wherein said interference means comprises at least one detent projectingfrom at least one of said pusher plate.
 18. The fastener holdingcartridge of claim 14 further comprising a knife means for cutting bodytissue, said knife means being movable between a proximal position inwhich said knife means is completely enclosed by said cartridge and adistal position wherein a cutting edge of said knife means projects outof a corresponding slot in the distal end of the cartridge, saidmovement of the knife means being in response to movement of said lineardrive force.
 19. The fastener holding cartridge of claim 18 furtherincluding resilient means for biasing said knife means to its proximalposition.
 20. The fastener holding cartridge of claim 19 wherein saidresilient means comprises a leaf spring.
 21. The fastener holdingcartridge of claim 14 wherein said means for restraining the orientationand movement of the cam bar comprises at least one first member whichprojects from the cam bar and is fixedly attached thereto, and at leastone second member which is associated with the fastener holdingcartridge, said second member having at least one guide slot forreceiving said first member and for restraining its movement to apredetermined path.
 22. The fastener holding cartridge of claim 21wherein said second member is stationary relative to the fastenerholding cartridge.
 23. The fastener holding cartridge of claim 22wherein said second member is a side plate.